Bowen Amy J, Reynolds Andrew G, Lesschaeve Isabelle
Cool Climate Oenology and Viticulture Institute (CCOVI), Brock University, St. Catharines, ON L2S 3A1, Canada.
Food Res Int. 2016 Nov;89(Pt 1):591-603. doi: 10.1016/j.foodres.2016.09.005. Epub 2016 Sep 4.
There is likelihood that periods of freezing and thawing endured by icewine grapes change their chemical and sensory profiles. The experimental objective was to determine the influence of harvest date and crop level on icewine sensory profiles and their relationships with chemical variables. Riesling and Vidal blanc (hereinafter "Vidal") icewines were made from four harvest dates in 2004-2005; Harvest 1 (H1): 19 December; H2: 29 December; H3: 18 January; H4: 11 February (Vidal only). Riesling and Vidal icewines were additionally made from three crop level treatments [control (fully cropped), fruit set cluster thinning (i.e. partial fruit removal) to one (basal) cluster per shoot, veraison cluster thinning] and were evaluated over two seasons (2003-2004; 2004-2005). Triangle tests showed differences between harvest date and crop level treatments (both cultivars). Ten and 11 aroma/flavor attributes differed for Vidal and Riesling harvest date icewines, respectively, based upon descriptive analysis by 14 trained tasters. For Vidal, later harvest dates had higher aroma/flavor intensities than H1. Riesling H1 wines had highest fresh fruit descriptor intensities whereas H3 wines were highest for dried fruit and nutty descriptors. Partial least squares regression (PLS) found Vidal icewines described by dried fruit/raisin and honey flavors and viscosity; these attributes were correlated to several aroma compounds and associated with later harvest dates. Sensory differences existed between crop level treatments; thinned treatments had higher fruity, honey, sherry and nut aroma/flavor intensities (both cultivars). PLS showed that sherry flavor was the most important explanatory variable in 2003, and correlated 4-vinylguaiacol and banana flavor in 2004. Overall, harvest date and crop level both affected sensory profiles and chemical composition of Niagara Peninsula icewines.
冰酒葡萄经历的冻融期有可能改变其化学和感官特征。实验目的是确定采收日期和作物负载量对冰酒感官特征的影响以及它们与化学变量之间的关系。雷司令和维代尔白（以下简称“维代尔”）冰酒由2004 - 2005年的四个采收日期的葡萄酿制而成；采收1（H1）：12月19日；H2：12月29日；H3：1月18日；H4：2月11日（仅维代尔）。雷司令和维代尔冰酒还由三种作物负载量处理方式酿制而成[对照（完全结果）、疏花疏果（即部分果实摘除）至每新梢留一（基部）果穗、转色期疏果]，并在两个季节（2003 - 2004年；2004 - 2005年）进行评估。三角试验表明采收日期和作物负载量处理方式之间存在差异（两个品种均如此）。根据14名经过培训的品酒师的描述性分析，维代尔和雷司令采收日期冰酒分别有10种和11种香气/风味属性存在差异。对于维代尔，较晚的采收日期具有比H1更高的香气/风味强度。雷司令H1葡萄酒的新鲜水果描述符强度最高，而H3葡萄酒的干果和坚果描述符强度最高。偏最小二乘回归（PLS）发现维代尔冰酒可用干果/葡萄干、蜂蜜风味和粘度来描述；这些属性与几种香气化合物相关，并与较晚的采收日期有关。作物负载量处理方式之间存在感官差异；疏果处理的果香、蜂蜜、雪莉酒和坚果香气/风味强度更高（两个品种均如此）。PLS表明，雪莉酒风味是2003年最重要的解释变量，并在2004年与4 - 乙烯基愈创木酚和香蕉风味相关。总体而言，采收日期和作物负载量均影响尼亚加拉半岛冰酒的感官特征和化学成分。
